Formation of skin-core in carbon fibre processing: A defect or an effect?

eXPRESS Polymer Letters

S. Nunna¹ 

关键词: mechanical properties;    carbon fibres;    industrial applications;    processing technologies;    material testing;   

DOI  :  10.3144/expresspolymlett.2019.14

学科分类：生物科学（综合）

来源: eXPRESS Polymer Letters

【 摘 要 】

The influence of stabilized fibre structure and skin-core formation induced by rapid thermal stabilization of polyacrylonitrile(PAN) on the tensile properties of carbon fibres was investigated. Three sets of samples were prepared by stabilizingPAN fibres under three temperature profiles using a continuous carbon fibre processing line. Initially, the chemicalstructure and density variations in stabilized fibres were examined with respect to process conditions using Fourier TransformInfrared Spectroscopy (FTIR) and density column methods. Interestingly, while the cyclization and dehydrogenation indicesare similar for all the stabilized fibres irrespective of temperature profiles used, the densities of these fibres varied from 1.34to 1.366 g/cc. Micro-Raman studies showed the existence of structural heterogeneity in the fibres from low temperature(LT) carbonization (I(D)/I(G) ratio of core was ~5.6% higher than the skin) that eventually reduced with high temperature(HT) carbonization because of uniform sp3 to sp2 hybridization of carbons. However, modulus mapping revealed heterogeneousstorage modulus distribution in the HT carbon fibre cross-section from Trial-2 (storage modulus of core was ~23 GPaless than the skin). Interestingly, this heterogeneity did not show a significant effect on the bulk properties of carbon fibressuggesting skin-core formation is an effect rather than a defect.

【 授权许可】

CC BY